From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Petr Mladek <pmladek@suse.com>,
coverity-bot <keescook@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
linux-next@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: Coverity: console_prepend_dropped(): Memory - corruptions
Date: Tue, 17 Jan 2023 16:51:49 +0900 [thread overview]
Message-ID: <Y8ZTlVX3HQUVkU13@google.com> (raw)
In-Reply-To: <877cxl3abr.fsf@jogness.linutronix.de>
On (23/01/17 08:16), John Ogness wrote:
> On 2023-01-17, Sergey Senozhatsky <senozhatsky@chromium.org> wrote:
> > On (23/01/16 17:35), Petr Mladek wrote:
> >> len = snprintf(scratchbuf, scratchbuf_sz,
> >> "** %lu printk messages dropped **\n", dropped);
> >
> > Wouldn't
> >
> > if (WARN_ON_ONCE(len + PRINTK_PREFIX_MAX >= outbuf_sz))
> > return;
> >
> > prevent us from doing something harmful?
>
> Sure. But @0len is supposed to contain the number of bytes in
> @scratchbuf, which theoretically it does not. snprintf() is the wrong
> function to use here, even if there is not real danger in this
> situation.
Oh, yes, I agree that snprintf() should be replaced. Maybe we can go
even a bit furhter and replace all snprintf()-s in kernel/printk/*
(well, in a similar fashion, just in case). I'm just trying to understand
what type of assumptions does coverity make here and so far everything
looks rather peculiar.
next prev parent reply other threads:[~2023-01-17 7:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 23:46 Coverity: console_prepend_dropped(): Memory - corruptions coverity-bot
2023-01-14 10:14 ` Sergey Senozhatsky
2023-01-16 16:35 ` Petr Mladek
2023-01-17 3:07 ` Sergey Senozhatsky
2023-01-17 7:10 ` John Ogness
2023-01-17 7:51 ` Sergey Senozhatsky [this message]
2023-01-17 11:20 ` Petr Mladek
2023-01-18 0:35 ` Sergey Senozhatsky
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